Awareness of the danger of a phenomenon known as Arc Flash has increased in recent years within the field of electrical system design (Ref. 1). Arc Flash can occur when an electrical short circuit causes an extreme current. This current can destroy the faulting device and leave behind a path of ionized air similar to a small lightning bolt. The resulting light, heat, and pressure can injure or kill nearby personnel (Ref. 2). The capacity of any energized electrical part to generate an Arc Flash is determined by the magnitude of electrical current created by a short circuit at the part. This current magnitude is largely determined by the value of the Equivalent Inductance of the electrical circuit supplying the energized part (Ref. 3).
This available short circuit current value is also important when specifying fuses, breakers and other electrical system components (Ref. 4). Thus the Equivalent Inductance at different points in an electrical distribution system is of great importance to system design and safety.
The value for Equivalent Inductance used in the existing state of technology is estimated in part by the summation of nameplate data for components in the sourcing electrical circuit (Ref. 5). This may involve an extensive review of electrical diagrams. Also a time and labor consuming study of the physical distribution system may be needed to ascertain cable length, routing methods etc. These characteristics are also factored in equations used to estimate Equivalent Inductance at various points in an electrical system (Ref. 5).
Drawbacks to this current state of technology include:    1. The process is complex and expensive.    2. The results can become obsolete when the electrical system is modified.    3. Simplifying assumptions often used degrade the accuracy of the results.    4. The effects of parallel connections of motors, coils or other loads are too numerous and varying to be accurately accounted for.